Coal-feeder.



G. F. DE WEIN.

COAL FEEDER.

APPLICATION FILED 0012.20, 1911.

1,023,418. Patented Apr. 16, 1912.

IN VE NTOFL WITNESSES- horizontally disposed blastpipe 11.

unrriin s'ra'rns Pagan-'1 OFFIOE.

GEORGE F. DE "WEIN, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERSCOMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF NEW JERSEY.

COAL-FEEDER.

To all whom it may concern Be it known that I, Gannon F. Du lVElN, acitizen of the United States, residing at Milwaukee, in the county ofMilwaukee and State of \Visconsin, have invented a certain new anduseful Improvement in Coal-Feeders, of which the following is aspecification. This invention relates to improvements in theconstruction of feeding devices particularly adapted to feed acontinuous charge of pulverized or partially pulverized, fuel to thecombustion chamber of a kiln or furnace. The object of the invention isto provide a feeding device adapted to feed a continuous charge ofpulverized fuel or similar substances to the combustion chamber of afurnace or the like, which is simple in construction and eflicient inoperation.

Another object of the invention is to provide a feeder which can befreely substituted for the various forms of fuel feeders now in use, byslightly changing the inclosing casing and, possibly, the drivingmechanism.

Aclear conception of several embodiments of the invention can be had byreferring to the accompanying drawing forming part of thisspecification, in which like reference characters designate the same orsimilar parts in different views.

Figure 1 is a fragmentary central vertical section through a powderedfuel feeding device and blast pipe of a type used for feeding pulverizedcoal to the combustion chamber of cement kilns. Fig. 2 is a fragmentarycentral vertical section through the discharge end of a modified form offeeding device.

The feed hopper 1 is provided at its lower end with a'semi-circularinlet trough 6, one end of which connects with a horizontally 'outwardlyprojecting circular casing 2 formed of sheet metal or similar material.The outer free end of the circular casing 2 terminates near themid-portion of the interior of the screen casing or housing 7. Thedischarge conduit 10 connects the lower end of the screen casing orhousing 7 'withha T e air inlet pipe 13 terminates within the nozzle 12,which nozzle is directed toward the discharge end of the blast pipe 11in line with its axis.

The rotatable conveyer shaft 4 is concen- Specification of LettersPatent.-

Patented Apr. 16, 1912.

Application filed October 20, 1911. Serial No. 355,699;

trically mounted within the trough 6 and easing 2 and carries theconveyer screw 3. The shaft 4 is adapted'to be rotated at variable speedby means consisting of a driving belt taking over the conepulley 5 fixedto the end of the shaft 1. The conveyer screw 3 extends from the end ofthe inlet trough (3 through the trough 6 and easing 2 terminating flushwith the free end of the casing 2 Within the housing 7. The screen 8 isslightly conical in shape and is mounted concentrically upon theconveyer shaft 4 within the housing 7, see Fig. 1. The portion of thescreen 8 having smallest diameter surrounds and overlaps the free end ofthe casing 2, the end of the casing 2 projecting within the screen 8 foronly a short distance. A relatively large discharge passage 9 existsbetween the end of the screen 8 and the end of the screen casing orhousing 7.

In the modification, see Fig. 2, the conveyer shaft 24 which carries theconveyer 23 is rotatably and concentrically mounted within the casing22. The screen 28 is eylindrical in form and is mounted concentricallyupon the shaft 24, being adapted to rotate with the shaft. The casing 22project-s within the screen 28 to the mid-portion thereof, the screen28, however, being of considerably larger diameter than the easing 22.Relatively large discharge passages 29, 30, exist between the ends ofthe screen 28 and the ends of the inclosing casing or housing 27. Thedischarge conduit 31 forms a connection between the discharge openings29, 30, and the blast pipe, not shown.

During the operation of the device, see

Fig. 1, air under pressure is admitted through the air pipe 13 andnozzle 12 to the blast pipe 11. Pulverized, or partially pulverized,fuel such as coal or other suitable material, is admitted to the hopper1, falling directly into the path of the exposed portion of the conveyer3 within the trough 6. The conveyer 3, which is given a rotary motion bymeans of suitable ower applied to the cone pulley 5, gradual y forces oradvances the pulverized fuel toward the opposite free end of thecylindrical casing 2. Since the discharge from the end of the casing 2,due to the action of the conveyer screw, is more or less intermittent,and as it is desirable to have this discharge as uniform and regular aspossible, means is provided in the form of the rotary screen 8 forequalizing the discharge. .As the fuel is discharged from the casing 2to the interior of the revolving conduit 10 through the screen openingsor Since all the material dis-' perforations. charged from the end ofthe casing 2 cannot immediately pass through the screen 8, a portionthereof will be advanced by the action of gravity and due to the conicalformation of the screen 8 and the rotation of said screen, toward thedischarge passage 9. This advancing and subsequent distribution of thefuel over considerable longitudinal extent of the screen 8, causes acontinual discharge of niaterial to the blast pipe 11, since fuel willbe discharged at numerous points along the length of the screen 8, andlarger lumps of the substance which are unable to pass through thescreen 8 Will be discharged over the end thereof through the relativelylarge discharge opening or passage 9. The fuel discharged from thescreen 8 to the conduit 10 passes by gravity to the blast pipe 11through which it is carried by the injected air entering through thenozzle 12 to the combustion chamber of the kiln.

During the operation of the modified form of feeding device, see Fig. 2,the pulverized material passing through the cylindrical casing 22 by theadvancing action of the conveyer screw 23 is discharged from the freeend of the casing 22 to the .mid-portion of the revolving cylindricalscreen 28. A portion of the pulverized fuel thus admitted to theinterior mid-portion of the cylindrical screen 28 passes directlythrough the screen perforations to the discharge conduit 31. Since thequantity of the material discharged from the casing 22 by the conveyeris'too great to immediately pass through the screen 28, the enteringmaterial piles up within the revolving screen 28 and is spread over theentire longitudinal extent of the screen. This distribution of thematerial Within the screen 28 produces a gradual discharge of fuel tothe conduit 31 since fuel passes through the screen 28 at various pointsalong the length thereof. The particles which are too large and henceunable to pass directly through the screen 28, are discharged over thetwo ends of the screen through the discharge passages 29, 30.

It should be noted that the device can be easily substituted for theordinary feeder now in use, which consists of a conveyer screwdischarging directly into a. passage leading to the blast pipe withoutthe interposition of-a screen or similar device, -by merely affixing therevolving screen 8, 28, to the conveyer shaft so that same slightlyoverlaps the end of the conveyer screw. It

should also be notedthat the use of a revolvmg, rather than astatlonaryscreen, choking of the screen perforations is not as liable tooccur.

It is not desired to be limited to the exact details herein shown anddescribed since Various modifications will appear to a person skilled inthe art.

It is claimed and desiredto secure by Letters Patent, I

1. In a feeder, a housing, a stationary casing communicating with saidhousing, a

shaft rotatable within said casing, a conveyeFfixed to said shaft, andfreely mounted within said housing a circular screen fixed to said shaftadjacent the end of said casing, said casing being adapted to dischargeto the interior of said screen.

2. In a feeder, a housing having a discharge conduit, a continuouslyrotatable round screen freely mounted Within said housing, and means fordelivering there- Within intermittent charges of material, said screenbeing free to dlscharge over its edge and said discharge. conduit beingadapted to receive said discharge and the material passing through saidscreen.

In a feeder, a casing, a shaft rotatable within and relative to. saidcasing, a conveyer fixed on said shaft, a screen fixed to said shaftadjacent the end of said conveyer, anda housing for said screen saidhousing having a discharge conduit, the end of said screen being spacedfrom said housing whereby material delivered to said screen will passtherethrough and over the end In testimony whereof, the signature of theinventor is affixed hereto in the presence of two witnesses. 4

GEORGE F. DE WEIN.

Witnesses:

W. H. LIEBER, CHAS. L. BYRON.

